Process of making grease



March 17, 1925.

J. MCKEE ET AL PROCESS OF MAKING GREASE Filed July 29, 1921 w x K,

Patented Mar.i17, 1925. i

UNITED STATESl r1,530,386 PATENT OFFICE.

vamicus iirexnie.,F or CHESTER, AND SAMUEL B. EGKERT, or DEvoN, PENNSYLVANIA,

AssIGNoRs To sUN on. COMPANY, or PHILADELPnIA, PENNSYLVANIA, A con- PORATION 0F NEW JERSEY.

PROCESS OF MAKING GREASE.

Application v:tiled July 2Q, 1921. Serial No. 488,272.

ToI all whom t concern.'

Be it known that we, JAMES MCKEE and SAMUEL B. ECKERT, citizens of the United States, residing at Chester, county of Delav Ware, and State of Pennsylvania, and at Devon, county of Chester, State of Pennsylvania, have invented a new and useful V Improvement in -Processes of Making Grease, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this spe'cication.

The object of our invention is to provide a grease for mechanical lubrication that, in its combined qualities, is superior to ordinary grease and more economical of manufacture. 'Such a grease is described and claimed in a separate application-,tiled by us July 29, 1921, Serial No. 488,271. The present invention. comprises a process that .is especially adaptable to the manufacture of oui` improved grease and without which the successful manufacture of such grease ,may be dicult or impossible. inasmuch as our process is not suitable for the mannfacture of ordinary grease, they process involves the utilization of the particular ingredien-ts ofwhich our improved grease is composed as well as deiinite mechanical and heat treatments.' n carrying .out the process we prefer to use an apparatus similar to that shown in the accompanying drawing, which is an elevation, more or less diagrammatic, of the same.

The apparatus comprises a grease still a having a vapor stack or vent b and an Archimedean screw agitator c.l An outflow ,Y pipe al, in which' is interposed a pump e,

connects with a cooler and agitator. The .cooler and agitator comprise aseries of pipes f, through which the grease is adapted to flow. lila-ch pipe contains an Archimedean screw conveyor g adapted to scrape the `inner walls `of the pipes. Each pipe is ja-cketed at 71, to provide acold water circulation, adjacent jackets being connected to allow the water to ilow yfrom the jacketof one pipe to the jacket of another in the reverse drtion to the direction of flow of the grease. The grease outiiow pipe i from the cooler and a 'tator discharges into a water-jacketed ag1tator and storage tank` j equipped with paddlesfk. A valve m regulates the outow of the finished grease into tive from mineral lubricating oil, a saponifiable mineral oil and a ,vegetable or animal oil, with a quantityof an alkali solution, preferably thirty Baume caustic soda, sutticient to neutralize all the saponifiable matter contained in the complete mixture. Usagewill determine the quantity o f alkali required. An amount somewhat less than that so determined is iirst added andv thereafter small quantities are added until, by successive titrations, the neutralizing point is found to be reached. Y

The preferred total proportion of the saponiied ingredients is not necessarily different from that characteristic of ordinary greases, although preferably such proportion slightly exceeds that of the 'saponified vegetable or animal oil used in ordinary greases.

The proportion of vegetable or animal oil, however, in our improved grease is substantially less than that of the vegetable or animal oil in ordinary greases. The fact that a saponified mineral oil derivative is used in partial Substitution for a saponified animal or vegetable oil and that such derivative is substantially cheaper than any ordinarily available vegetable oranimal oil, effects a material saving in cost of production. There is no practical minimum limit to the percentage of vegetable or animal oil and we have succeeded in producing. etlicient greases which contain no ingredient whatever of vegetable or animal oil; but

'. such greases do not have the density that centage of sulfur,V usually much less than one er cent, and when saponied being solub e in all proportions with Water and wholly or partially soluble in mineral oil and adaptedjo undergo'the character of /hydrolytic .decomposition that occurs with splaps derived from animal and vegetable o is `free-from parane.

'Ihe Maitland product that we prefer to use is a liquid and when saponiied entirel, soluble in all proportions with mineral oil It is prepared by distilling from crude petroleum a relatively heavy distillate adapted for lubricating'oil stock, treating the same with a mineral acid and separating out the precipitated sludge with a large part of the acid, treating the remaining ody of acid-containing oil with an alkali separating' out the precipitated soap and Y ese saponiable derivatives from mineral oil and certain processes of `making them are more specificallyl described in the Maitland Patents No. 1,425,882, No. 1,425,883, No. 1,425,884 and No. 1,425,885,

all issued August 15,1922. Patents `No.-

1,425,882 .and No. `1,425,884 set fbrth the Maitland product specified above as' preferable and the preferred process of making such product. As stated in the-specifications the saponified fatty acids produced by the processtherein-described are admixed with more or less mineral lubricating oil, the percentage of which will vary more or less. It `is this product', which may or ma not be produced by the process describe in the of Patents No. 1,425,882 and No.11,42 5,884,

' lastnamed patents, which we utilize in the manufacture of vo ur improved grease. There is no occasion," in using this product, to separate the mineral lubricating oil from the fatty acids, because our new product contains both fatty acids and lubricating min- ,completely separated from, the mineral oil,-

the proportion of fatty acids used -in our process would be lreduced from the-proportion, or range of proportions, herein specified for herein specified the -sa'ponification value of the Maitland fattyacids that we have usually used, from which the preferable proportions of thev pure fatty 'acidcan be readily I calculated.

We have also foundit advantageous, ifnot necessary, to manufacture the above saponifiable mineral oil derivative from a crudeI petroleumy that contains not over a small proportion of parailine. The .best results 'areobtain'ed from Gulf Coast crude, which a mineral Our experiments with various vegetable and animal oils lead us to believe that any saponiable vegetable or animal oil is available; and in restricting the claims to a vegetable oil it will be understood that we mean to include animal oil as an equivalent. As examples of workable and satisfactory saponiiiable non-mineral oils may be menticlmed tallow, horse oil', corn oil and caster o1 It is impossible to make very definite specifications of permissible percentages of 'the ingredients mentioned, since lit is desirable to make different kinds of grease, each of which is best adapted for a particular lubricating field. These different kinds of grease require considerable variations in percentages of the several ingredients. 1n all cases, however, the proportion of unsaponiliable mineral oil (which should be refined lubricating` oil) is several times that 'of the other ingredients combined, while the proportion of the saponitiable vegetable or animal oil may vary from zero to a proportion slightly, but not substantially, in excess of the proportion of the saponiiable mineral oil derivative. Thus, we have made greases containing from fifteen to twenty per cent of 50 'saponicatiom Maitland fatty acid with no vegetable. or animal oil; and on the other hand we have'made greases containing approximately nine per cent of 50 saponi-fication Maitland 'fatty acid i' and approximately as high as ten per centk of vegetable or animal` oil.v Usually, howl.

ever, when the percentage of vegetable or animal oil is reduced the' percentage of Maitland fatty acid is increased,

v A typical grease that gives excellentresults comprises refined lubricating mineral oil, 85%; 50 saponilicationMaitland fatty 'p acid, 9%; and tallow, 6%.

After charging the still a as hereinbefore'- stated, with the ingredients specified, the agitator c is put into motion'andy fire started under the still. The temperature'of the still I is slowly raised to slightly -over`f212 degrees F., at which point the fire is held in check v and the moisture resulting from Vthe addition of the soda solution slowly driven-olf.

While the period during which the wateris 'being boiled off and the reaction of alkali Maitland fatty acids. We have'and saponifiable material is taking place may be shortened to the actual time required uto boil oi the Water Without causing the still to boil over, it is advisable to hold thestill at the temperature specified for at least four hours in order to insure complete the'water, the mixture is raised rapidly to about 340 degrees F., after which the burners are turnedo" and the mixture pumped outi'of the still into and through the 'cooler and agitator. Here the mixture is gradually cooled by the reverse flow of mal or vegetable-oil.

cold Water through the pipe jackets h. The screws g assist in conveying the grease through the cooler and mix and agitate the grease, and by keeping the inner Walls of the pipes f scraped clear of grease, considerably facilitate transfer of heat.

By providing a sufficient length of pipes and screws, the grease may be discharged ,from the agitator and cooler in 'a finished condition; but We prefer to discharge the grease into the tank j and there subject it to further agitation and mixing, the paddles c also assisting in forcing the grease through the valved discharge into suitable containers. A

The ultimate product is entirely free from moisture.. The expulsion of moisture does not, however, sacrifice any advantage whatever that results from the Water-content that is present in` ordinary grease composed ot' mineral oil Worked into a saponilied ani- The grease may be raised to a temperature substantially 'in excess of the boiling pointgof Water and indeed to the flash p oint of :the oil Without any decomposition of`;tl i j' Grease and with .no effect upon it exciejptt increase its fluidity. Upon cooling sueh4 a higher temperaturefthe grease'reyeitts "to precisely the condition it was in before heating. Extreme.

cold effects viscosity only in degree, there being no hardening. In fact the grease has a cold test equal, if not superior, to the mineral oil or oils from which it islargely made. Thus,'a grease made from a mineral oil having a cold test varying from thirty to forty degrees below zero F. will have the same or a lower cold test. The grease, in its preferred embodiment, is neutral in reaction, it being unnecessary, as in the case of many greases, to carry `it Well on` the alkaline side. The greases do not oxidize and do not leave a hard or soapy residue when left for a prolonged period in `small oil passages or when maintained at a -high temperature for a long period. Thus quality is of especial importance when the grease is used for lubricating spring shackle bolts and other elements that are greased only periodically and then left .ex-'posed to the air for a prolonged time.

. Having now. fully` described our invention, What we'claim and desire to protect by Letters Patent is :--v

l1.- The process ofmanufacturing grease.'-

Which comprises mixing with unsaponiable mineral oil a saponiliable fatty acid mineral oil derivative and a saponifying agent and heating to a temperature at least equalv to the boiling point of Water until the Water is driven off and the desired saponification of the saponiiable material is effected, and then agitating and cooling.

2. The process of manufacturing grease.

which comprises mixing unsaponitiable mineral oil' with vegetable oil, a saponiiable fatty acid mineral oil derivativel and a saponifying agent and heating to a temperature latleast equal to the boiling point of Water until the Water is driven off and the desired saponifcation of the saponifiable material is effected, and' then agitating and *Cooling 3. The process of manufacturing grease comprising mixing unsaponifiable mineral oil with a saponifying agent and a waterinsoluble saponitiable fatty aci/d mineral oil derivative adapted when saponified to be entirely soluble in such mineral oil, and heating to a temperature at least as'high as the boiling point of Water until the water is driven ofi:` and the desired saponification of the saponiable material is effected, and then agit-ating and cooling.

4. The process of manufacturing grease which comprises mixing with unsaponifiable min-eral oil a' saponiliable mineral oil derivative and a saponifying agent, heating to a temperature at least as high as the boiling point of Water, maintaining such temperature Luntil the Water is substantially driven off, rapidly and substantiall elevating the temperature to increase flui ity, and

then agitating and cooling.

5. The process of manufacturing grease which comprises mixing unsaponifiable mineral oil with vegetable oil, a saponiiable mineral oil derivative and a'risaponi ing agent and heating togatemperature at east equal to the boiling piqit of yvater7 maintaining such temperature until the water is substantially driven'oiij',"rapidly and substantially elevatingjthe`temperature to in- .crease fluidity, and'ihenia'gitating and cooling.

mineral 'oil a saponifia, l e'inineral oil derivative and a saponifylilffgA-.agent, heating toL `which comprises mixing unsaponifiable m111- x eral oil with vegetable oil, a saponiable mineral oil derivative and a saponifying agent and heatingto a temperaturefat least equalfto the boiling point of water until the Water is driven off and the desired saponi-` ication'of the saponiiable material is effected, and conveying the grease along an extended path and during its' travel agitating it and maintaining it in heat exchange relation with a cooling medium. Y'

The processof iiafnifacturing grease Which comprises mixinyyith unsaponiable v 7. The processpf manufacturinggrease j len' 8. The process 'of manufacturing grease ,l

which comprises mixing unsaponifiable mineral oil and a saponifiable mineral oil derivative and a saponifying agent, heating to a temperature at least as hlgh as the boiling point of Water, maintaining such tempera- -ture until the water is substantially driven` ofi", rapidly and substantially elevating the temperature to vincrease iuidity, and conveying the grease along an extended path and during its travel agtating it and main` taining it in heat exchange relation with a cooling lmedlum.

9. The process of manufacturing greasewhich comprises mixing unsaponiiable min- 'eral oil AWith vegetable oil, a saponifiable mineral oil derivative and a saponifying agent an'd heating to a temperature at least equal to the boillng point of Water, maintaining' such temperature until the water is,

substantiall driven off, rapidly and substantiall .e evatlng the temperature to increase uidity,l and conveymg the grease along an extended path and during its travel 'agitating it and maintaining it in heat exchange relation with alcooling medium.

10. The process of manufacturing r1-ease which comprises mixing with unsaponlfiable mineral oil a'saponiable mineral oil derivative' and a saponifying agent heating to a 'temperature at least as high as the boiling point of water, maintaining such temperature until the water is driven oif and the desired Saponification 'of the saponiiiable material is electedfelevating the temperature to increase fluidity, conveying the grease along an extended path and during its travel agitating itand maintaining it in heat ex- SAMUEL B. ECKERT. 

